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#include <cmath>
#include "QxGuide.hpp"
#include "QxColors.hpp"

QxGuide::QxGuide( QxGuide* follows )
{
  this->scaleX = 1.0;
  this->scaleY = 1.0;

  if( follows ) {
    while( follows->nextGuide != follows->firstGuide ) {// append to end
      follows = follows->nextGuide;
    }

    follows->nextGuide = this;
    this->prevGuide    = follows;
    this->firstGuide   = follows->firstGuide;
    this->nextGuide    = follows->firstGuide;
    this->startLength    = int(follows->startLength + follows->length()) + 1;
  } else {
    this->prevGuide    = this;
    this->firstGuide   = this;
    this->nextGuide    = this;
    this->startLength    = 0;
  }
}

void QxGuide::setScale( float scaleX, float scaleY, bool all )
{
  this->scaleX = scaleX;
  this->scaleY = scaleY;

  if( all ) {
    QxGuide* next = this->nextGuide;
    while( next != this ) {
      next->scaleX = scaleX;
      next->scaleY = scaleY;
      next = next->nextGuide;
    }
  }
}

void QxGuide::setFence( const QRectF& fence, bool all )
{
  this->fence = fence;

  if( all ) {
    QxGuide* next = this->nextGuide;
    while( next != this ) {
      next->fence = fence;
      next = next->nextGuide;
    }
  }
}

QxGuide::~QxGuide()
{
  if( this != this->nextGuide && this->nextGuide != this->firstGuide ) {
    delete this->nextGuide;
  }
}

float QxGuide::lengthAll()
{
  float len = length();
  QxGuide* next = this->nextGuide;
  while( next != this ) {
    len += next->length();
    next = next->nextGuide;
  }
  return len;
}

void QxGuide::move( QxDemoItem* item, QPointF& dest, float moveSpeed )
{
  QLineF walkLine( item->getGuidedPos(), dest );
  if( moveSpeed >= 0 && walkLine.length() > moveSpeed ) {
    // The item is too far away from it's destination point.
    // So we choose to move it towards it instead.
    float dx = walkLine.dx();
    float dy = walkLine.dy();

    if( qAbs(dx) > qAbs(dy) ) {
      // walk along x-axis
      if( dx != 0 ) {
        float d = moveSpeed * dy / qAbs(dx);
        float s = dx > 0 ? moveSpeed : -moveSpeed;
        dest.setX( item->getGuidedPos().x() + s );
        dest.setY( item->getGuidedPos().y() + d );
      }
    } else {
      // walk along y-axis
      if( dy != 0 ) {
        float d = moveSpeed * dx / qAbs(dy);
        float s = dy > 0 ? moveSpeed : -moveSpeed;
        dest.setX( item->getGuidedPos().x() + d );
        dest.setY( item->getGuidedPos().y() + s );
      }
    }
  }

  item->setGuidedPos( dest );
}
